What are the causes of biliary dilation (bile duct dilation)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: April 28, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Biliary dilation should be promptly evaluated and treated to prevent serious complications, with endoscopic intervention being the preferred initial approach for dominant strictures, as recommended by the most recent guidelines 1. When biliary dilation is identified, further evaluation is necessary to determine the underlying cause. The most common causes include gallstones, tumors (such as pancreatic cancer or cholangiocarcinoma), strictures, and inflammation. Patients with biliary dilation may present with symptoms like jaundice, abdominal pain, fever, and dark urine, though some cases are asymptomatic and discovered incidentally.

Diagnostic Workup

Diagnostic workup typically includes:

  • Laboratory tests (liver function tests, bilirubin levels)
  • Imaging studies (ultrasound, CT, MRI/MRCP)
  • Possibly endoscopic procedures like ERCP Treatment depends on the underlying cause and may include endoscopic stone removal, stent placement, surgery, or antibiotics for infection.

Treatment Approach

The treatment approach for biliary dilation has evolved over time, with endoscopic intervention becoming the preferred initial approach for dominant strictures, as seen in a study published in the Journal of Hepatology 1.

Endoscopic Intervention

Endoscopic intervention, such as balloon dilation or stent placement, can improve symptoms and liver biochemistry, and may reduce the risk of recurrent cholangitis, as reported in a study published in Gut 1.

Recommendations

The most recent guidelines recommend endoscopic intervention as the initial approach for dominant strictures, with balloon dilation being preferred over stenting due to lower complication rates 1. In cases where endoscopic intervention is not possible or unsuccessful, percutaneous or surgical approaches may be considered.

Prognosis

The prognosis for patients with biliary dilation varies widely depending on the underlying cause, with benign conditions generally having better outcomes than malignant ones. Prompt evaluation and treatment are essential to prevent serious complications and improve patient outcomes.

From the Research

Biliary Dilation Overview

  • Biliary dilation, also known as biliary obstruction, occurs when the flow of bile from the liver to the small intestine is blocked, causing the bile ducts to dilate.
  • The etiology of secondary intra- and extrahepatic bile duct dilatation can be classified into obstruction-, lesion-, and compression-induced dilatation 2.

Causes of Biliary Dilation

  • Biliary strictures, which are narrowings of the bile ducts, can cause biliary dilation 3.
  • Tumors, such as cholangiocarcinoma, can also cause biliary dilation by obstructing the bile ducts 4, 5.
  • Stones in the bile ducts can cause biliary dilation, and treatment may involve endoscopic dilation or stenting, or laparoscopic choledochectomy for stone removal 2.

Treatment Options for Biliary Dilation

  • Endoscopic retrograde cholangiopancreatography (ERCP) is a common procedure used to treat biliary dilation, and is successful in 90% of cases 6.
  • Endoscopic ultrasonography-guided biliary drainage (EUS-BD) is an emerging alternative to percutaneous transhepatic biliary drainage in cases with failed ERCP 6, 4, 3.
  • Percutaneous transhepatic biliary drainage (PTBD) is another option, but has a higher adverse event rate compared to endoscopic drainage 5.
  • Treatment varies depending on the cause of the biliary dilation, and may involve endoscopic dilation or stenting, laparoscopic choledochectomy, or resection for cholangiocarcinoma 2.

Advantages and Disadvantages of Treatment Options

  • Endoscopic biliary drainage has a lower adverse event rate compared to percutaneous biliary drainage, especially for patients with pancreatic cancer 5.
  • EUS-BD is a effective salvage option for perihilar malignant biliary obstruction, which cannot be managed via ERCP or percutaneous transhepatic biliary drainage 3.
  • The technical success rate of balloon enteroscopy-assisted endoscopic retrograde cholangiopancreatography (BE-ERCP) is not always high, and EUS-BD can be used as a second-line therapy in failed BE-ERCP cases 4.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.